Perioperative ST-segment depression is rare and may not indicate myocardial ischemia in moderate-risk patients undergoing noncardiac surgery

Objective: To identify a group of older asymptomatic patients in whom ST-segment changes are common and determine their correlation with occult coronary artery disease. Design: Prospective, cohort study. Setting: University hospital, single-center. Participants: Patients older than 45 years with at least one risk factor for coronary artery disease but without documented disease undergoing noncardiac, nonvascular surgery. Interventions: Intraoperative and early postoperative continuous electrocardiographic monitoring, exercise treadmill testing, 24-month telephone follow-up. Measurements and Results: A total of 190 patients were studied with a continuous ST-segment monitor, seven of whom demonstrated significant ST- segment changes during the intraoperative or early postoperative period. Three of the seven patients were evaluated by exercise treadmill testing, all of whom had a negative test. Follow-up was complete in 84% of the cohort without ST-segment changes and in all patients with ST-segment changes. One patient with perioperative ST-segment changes died of prostate cancer. None of the other patients showed any symptoms of coronary artery disease on follow-up. Conclusion: ST-segment changes are rare during the intraoperative and immediate postoperative period in asymptomatic patients at moderate risk for coronary artery disease. The low incidence of a positive stress test and lack of cardiovascular symptoms on follow-up in patients with perioperative ST-segment changes suggest that caution should be exercised before diagnosing myocardial ischemia and coronary artery disease.